Fluid-Maxwell simulation of laser pulse dynamics in overdense plasma

A one-dimensional model of collisionless electron plasma, described by the full system of Maxwell and relativistic hydrodynamic equations, is exploited to study the interaction of relativistic, strong, circularly polarized laser pulses with an overdense plasma. Numerical simulations for the ultrarelativistic pulses demonstrates that for the low as well as for the high background density, the major part of the penetrated energy remains trapped for a long time in a nonstationary layer near the plasma front end; only a minor portion resides in solitons. Important details of the interaction for the moderately intense and strongly relativistic pulses for semi-infinite and thin plasma layers are revealed. An interesting additional consequence of the long-time confinement of relativistic strong radiation in an overdense plasma is analyzed. It is shown that intensive pair production by the driven motion of plasma electrons takes place due to the trident process. (C) 2005 American Institute of Physics.